Effect of Low-Protein Non-Amino Acid Supplemented Diet and Ractopamine (Paylean) on Growth Performance and Serum Urea Concentration of Late-Finishing Pigs

University of Nebraska 2006 Swine Day Report. When feeding excessive amounts of protein, the nitrogen eliminated by the pigs in swine facilities has an important impact in the environment. Therefore, it is important to define nutritional strategies that promote a more efficient use of protein. This study was conducted to evaluate the effect of a low-protein non-amino acid supplemented diet and ractopamine (Paylean) on performance of late-finishing pigs. Thirty-six finishing barrows and gilts with an initial body weight of 153.4 lb were used in a 42-day experiment. Pigs were penned individually and had ad libitum access to feed and water. The pigs were randomly allotted to one of four dietary treatments with different dietary protein (10 or 16 % CP) and ractopamine (0 or 20 ppm) concentrations. Body weight and feed disappearance were measured weekly. Average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (ADG/ADFI) were calculated. Blood samples were collected weekly by venipuncture and serum was collected. Data were analyzed as repeated measures and by orthogonal contrast (to examine differences among means). There were treatment differences for ADG (P < 0.05) for the overall experimental period with the highest ADG (2.26 lb/day) correspondingto the pigs receiving 16% CP and 20 ppm ractopamine. There was no ractopamine effect on serum urea nitrogen( SUN) for any weekly period or overall. Average daily feed intake was lower for diets with 16% CP compared to diets with 10% without ractopamine (Paylean) results in similar growth performance. This was a preliminary study designed to establish a response range for dietary crude protein (CP) and ractopamine additions for pigs from the UNL herd.